81556111815703 has 16 divisors (see below), whose sum is σ = 93229458094080. Its totient is φ = 69888385512000.

The previous prime is 81556111815671. The next prime is 81556111815757. The reversal of 81556111815703 is 30751811165518.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 81556111815703 - 2⁵ = 81556111815671 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81556111855703) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 695581158 + ... + 695698396.

It is an arithmetic number, because the mean of its divisors is an integer number (5826841130880).

Almost surely, 2^{81556111815703} is an apocalyptic number.

81556111815703 is a deficient number, since it is larger than the sum of its proper divisors (11673346278377).

81556111815703 is a wasteful number, since it uses less digits than its factorization.

81556111815703 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 140358.

The product of its (nonzero) digits is 1008000, while the sum is 52.

The spelling of 81556111815703 in words is "eighty-one trillion, five hundred fifty-six billion, one hundred eleven million, eight hundred fifteen thousand, seven hundred three".